New York City mayor Michael Bloomberg will officiate at the wedding of his chief policy adviser, John Feinblatt, and his partner, Jonathan, Mintz, the city’s consumer affairs commissioner, July 24, the first day same-sex couples will be able to marry in the state.

Reuters reports on the event to take place at Gracie Mansion, the official residence of New York City mayors. It will be the third time Bloomberg has officiated at a wedding as mayor, having previously married one of his daughters and former mayor Rudy Giuliani.

"John and Jonathan have each done so much to make the city a better place, and together, they helped me see the issue of marriage equality in very clear terms," said Bloomberg in a statement reported by Reuters. "This will be one of the biggest days of their lives, a day they've waited a long time to see, and I'm just honored to be a part of it."

Feinblatt played a key role in the mayor’s efforts to help pass the Marriage Equality Act, which takes effect Sunday, July 24, after being signed into law by Gov. Andrew Cuomo last month. The mayor traveled to Albany to lobby Republican senators on the bill, delivered a high-profile speech, and contributed hundreds of thousands of dollars to the marriage equality advocates’ campaign.

Clerks' offices in New York City will be open that Sunday and have extended hours the following Monday through Friday to accommodate the expected influx of people. Same-sex couples from anywhere will be able to marry in New York, which has no residency requirement in the new law.